Fuel-feed system



F. E, EDWt-KEL FUEL FEED SYSTEM.

APPLICATION FILED SEPT. 13, 1918.

Patented Sept. 28, 1920.

2 SHEETS-SHEET 1- F. E. EDWARDS.

FUEL FEED SYSTEM.

APPLICATION man SEPT. 12 1918.

Patented Sept. 218 2 SHEETS-SHEET 2.

UNITED STATES. PATENT OFFICE.

FRANCIS E. EDWARDS, CHICAGO, ILLINOIS, ASSIGNOR T0 STROMBERG MOTOR DEVICES COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

FUEL-FEED SYSTEM.

Application filed September'13, 1918. Serial new and useful Improvement in Fuel-Feed Systems, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawin s, forming a part of'this specification.

Ily invention relates to fuel feed systems for automobiles and the like.

The present invention is an improvement upon my prior invention described and claimed in co-pending application, 'Serial Number 217,701 filed February 16th, 1918.' In that application I have described a pumping chamber operated by a column of air which serves as an elastic piston connecting a small impulse pump with the pumpingchamber. 'The impulse pump is driven directly and continuously by'the engine and is of a size such as to pump have conceived that this open vent can be dispensed with and the same results secured by providing an auxiliary chamber which serves when the vent valve is opened, to increase the effective volumetric capacity of the combined air and pumping chambers so that the impulses of the impulse pump are insufficient. in intensity to move the liquid fuel from the tank into the pumping chamber. The vent valve is constructed to open inwardly so that the advantage of accumulating pressure within the pumping chamber when the float valve is raised, can be secured.

'In order to teach those skilled in the art how to construct and practice my invention I shall now describe in connection with-the accompanying drawin of the present spec' cation, a particular embodiment of my invention.

Figure 1 is a diagrammatic layout ofthe Specificatiomof Letters Patent.

s which form a part' Patented Sept. 28, 1920. No. 253,972.

parts of my invention .showing the carbureter the pumping chamber the supply tank, the impulse pump and the auxiliary chamber s Fig. 2 is a plan viewof the pumping chambers; and

1g 3 is a vertical axial section of the pumping chamber and auxiliary chamber.

It is to be understood that while I describe my invention with reference to a particular embodiment involving the feeding auxiliary and of liquid fuel to a carburetor, it is to be understood that the invention is not limited to this purpose only but vmay be employed for other purposes, such as supplying lubricating oil to bearings or for general pumping purposes. The pumping chamber 1 is connected on its inlet side by the pipe 2 with the supply' tank 3 which may be placed at any convenient point in the vehicle,- and which, due to the design of modern automobiles must nearly always be placed below the level of the carbureter 4. The discharge side of the pump-. ing chamber 1 is connected by means of the pipe 5 with the float control valve (not shown) of the carbureter float chamber 6.

Thetop of the pumping chamber 1 is connected to the impulse pump 7 through the pipe or tube 8. The impulse pump 7 comprises a cylinder 9 having a suitable piston 10, which piston is connected by a connecting rod 11 and cam or crank 12 to a shaft 13 of the engine, which in this case may be considered as a cam shaft. The cylinder 9 is mounted by means of abracket lei'upon a suitable frame part 15 of the motor or the vehicle. The top of thecylinder 9 is closed by a head 16 to which is connected the pipe 8. The cylinder 9 and the pipe 8 define an air chamber in which there are set up .alternate impulses of compression and rarefaction due to the movement of the piston 10 which constitutes one wall of such air chamber. The'air in this chamber when thus subjected to rarefactions and compressionsoperates upon the surface of the liquid in the pumping chamber 1 in the nature of. an elastic piston. The pumping chamber 1 comprises a cup or .recep tacle 17 having 'a/ cover or head 18 which closely fits the top of the. cup 17. In the bottom of the cup 17 there is provided an integral extension 19 in which is locateda suitable dischargefclieck valve 20. An inlet stem 21 is threaded centrally into the bottom of the cup 17 and this stem provldes at its upper end a seat for the inlet valve 22.

The inlet housing 23 communicates with the interior of the hollow stem 21 and with the pipe 2, which connects with the supply auxiliary chamber 26 is threaded to the boss 'reter 4.

that its float valve closes off communication 27 on the cap 18, thus securing the auxiliary chamber 26 to the cap member 18 and in communication with the interior of the pumping chamber 1 by way of the valve port 25. The valve port 25 has a valve seat cooperating with the float controlled vent valve 28. The valve 28 has a stem 29 which extends down through the float member 30 and is adapted to engage the inlet check valve 22 to hold the same closed when the vent valve 28 is open. The valve 28 and its stem 29 are connected to the float 30 bymeans of the weighted levers 31. These weighted levers are PlVOtGd upon depending lugs 32 which are formed on the bottom of thecap 18. The cap 18 is also provided with an opening 33 which is connected to the pipe 8 and from thence to the pump '7. Suitable couplings for making these connections are provided. The head member 18 is provided with an extending bracket or lug portion 34 by which the pumping chamber may be suitably supported. In this case I have shown this bracket as connected to the inlet housing 35 of the carbureter float chamber 6.

The operation of the system is as follows: The pump piston 10 being connected directly to the engine and being operated in accordance with the speed of the same, causes alternate rarefaction and compression in the body of air contained within the pipe 8 and the top of the pumping chamber 1. These alternate compressions and rarefactions alternately discharge and draw fuel from and to the pumping chamber 1. On the rarefaction impulse, liquid fuel is drawn into the pumping chamber 1 and upon the compression stroke the inlet check valve closes and the discharge check valve 20 is opened and the liquid is forced therefrom through the pipe 5 to the float chamber 6 of the carbu- If the float chamber 6 is filled so between the pipe 5 and the float chamber 6, the compression impulses will be unable to move the liquid out of the pumping chamber 1 and the succeeding rarefaction impulse liquid into the pumping Whenthe level in the chamber 1 rises to a opened, as indicated in Fig. 3, the additional body of air contained in the auxiliary chamber 26 is put in communication with the body of air contained in the pump 7 and pipe 8 and the top of the chamber 1. The result of this is to reduce the effect of the pulsations of the impulse pump 7 to such a degree that the pulsations become ineffective to either draw fuel into the pumping chamber 1 or force the same out. The reason for this is apparent, namely that the greater the amount of air in communication with the impulse pump 7, the less effect will move ment of the piston 10 have upon the pressure of said body of air. I

I have shown the auxiliary chamber 26 as being in the form of a relatively long tube of relatively small diameter, but it is to be understood that the form and proportion of this chamber may be widely varied.

Inasmuch as the pump 7 is connected to the engine and runs synchronously with the same, it will be seen that the operation of the piston tends to maintain a constant movement of liquid from the tank-3 through the pumping chamber to the float chamber 6 of the carbureter and from there to the Consequently, complete opening of the vent valve 28 as shown in Fig. 3 does not occur during normal running. On the contrary, the tendency is to maintain the level of the liquid in the pumping chamber 1 very near the maximum level so that the vent valve is held closed with a very slight pressure. As the capacity of the pump is in excess of that required to pump suflicient gasolene to the carbureter 4, the vent valve 28 tends to move away from its seat as the engine.

chamber 1 becomes more nearly filled to its maximum level. When this occurs the the auxiliary chamber.

I do not intend to be limited to the precise details of construction shown and described.

I claim:

1. In combination, an air chamber having a movable wall for creating impulses of alternate compression and rarefaction, a

The rare- I auxiliary pumping chamber communicating with said air chamber, said pumping chamber having inlet and discharge valves, and a closed air chamber having means for permitting communication with said first named air chamber, said means being con trolled by the level of liquid in the pumping chamber. 1

2. In combination, an impulse pump for creating impulses of alternate compression and rarefaction, a pumping chamber, a closed auxiliary chamber adapted to have communication with the pumping chamber, and a float controlled valve governing the communication of the pumping chamber with the auxiliary chamber.

3 In combination, a pumping chamber, an auxiliary air chamber, an air impulse pump for creating impulses of alternate compression and rarefaction communicating with'the pumping chamber and through the pumping chamber with the auxiliary air chamber and a float controlled valve governing the communication between the auxiliary chamber and the impulse pump.

4. In combination, an air chamber having a movable wall for creating impulses of alternate compression and rarefaction, a pumping chamber communicating at its upper end with said air chamber, said pumping chamber having inlet and discharge valves, a closed auxiliary air chamber adapted to have communication with the pumping chamber and the air chamber, a float in the pumping chamber and a valve controlled by the float for controlling the communication of the auxiliary air chamber with said air chamber.

5. In combination, a pumping chamber, an air impulse pump communicating with said pumping chamber, an auxiliary air chamber, said chambers and said pump being adapted to have communication, and a float 'controlled valve governing the communication between the auxiliary air chamber and the impulse pump, said valve being adapted to open inwardly toward the impulse pump.

In witness whereof, I hereunto subscribe my name this 10th day of Sept, A. D. 1918.

FRANCIS E. EDWARDS. 

